Welcome to the uracoli Blog

µracoli stands for microcontroller radio communications library and is intended to be a package that demonstrates capabilities and usage of Atmel's IEEE-802.15.4 radio transceivers AT86RF{230,231,212} in combination with AVR 8 bit microcontrollers (e.g. ATmega16, ATmega1281, ATmega128RFA1, ...).

Dienstag, 18. April 2017

Abstract

Setting up an embedded tool chain on a local PC or laptop requires very often to spend an enormous amount of time for installation and configuration of the individual software packages. It ends up in a "golden" installation on a single computer that is kept like a treasure. But with each new package installed on this computer, the golden installation is in danger.
Docker provides a light weight virtualization engine that runs on Linux, Windows or MacOS.
Docker containers contain virtual guest OSes and can easily be configured, deployed and executed. The article descibes how to create a suitable container for embedded software development and how to use it.

Mittwoch, 31. Dezember 2014

Since there are a lot of leave trees in my garden, every year in autumn it is a busy time to remove the leaves from the ways and meadows. I was thinking what else can be done with this amount bio mass, then simply let it rot. Depending on the sort leaves it may rot slowly and it can take several years until a leave becomes soil.
Once a day I stumbled across the concepts of Jean Pain, a french lumberjack and inventor. He did setup huge piles of shreddered branches and observed that inside this piles high temperatures are achieved. Within such a pile water can be heated up to 70°C, this can be read on the internet. The reason is, that the shreddered bio mass rots aerob, e.g. in the presence of oxygen. In the logical consequence Pain added a heat exchanger in the pile and so he could use the energy generated by the bacteria to heat his house and he also could produce methane - natural gas - to drive cooking stoves, cars and agricultural machines. Pain's work is documented in the book The methods of Jean Pain or another Kind of Garden (or as online version). B.t.w. the german word "Biomeiler" can be translated with "heating compost".

Samstag, 22. März 2014

With a fine tradition we went on the second march weekend to Chemnitz to join the get-together of the open source community. This years topic was "Confidence is ...?" - so the focus was clearly on computer and internet security, but not only. The talks and workshops did cover many different areas, and therefore our presentation of the new Jenkins based test system was not completely off topic.

As guests we participated in the Django workshop by Andreas Hug and Markus Zapke-Gründemann. This workshop brought new insights, how easy it is today, to setup a powerfull web application. Three years ago in our presentation we handcrafted a lot, which can be achieved currently much easier and much more secure.

At the perfectly organized get-together-party on saturday evening we enjoyed to talk face to face with other developpers and the organizers of the event, while having a good beer and a tasty buffet.

All in all we enjoyed the stay as every year and even if the preparation phase is always a busy time, our oppinion is "See you again next year in Chemnitz".

Montag, 29. Juli 2013

Introduction

The µracoli team recently got one of the new RaspBee modules from dresden elektronik (DE) for evaluation. The RaspBee is a addon module for the popular Raspberry Pi computer and is equipped with an Atmega256RFR2. Due to its huge amount of RAM and FLASH and the integrated transceiver, this MCU is a smart choice for building ZigBee or IEEE 802.15.4 gateways.

The very popular Raspberry Pi needs probably no extra introduction. The credit card size ARM computer runs Linux (e.g. Raspbian) and it has USB and Ethernet interfaces, which makes it perfect for DIY projects.

Esentially the RaspBee consists of a radio module deRFmega256-23M12, is equipped with a ceramic chip antenna, the footprint for an U.FL coaxial connector, two LEDs and a (not populated) JTAG connector. The 12 pin header connects the RaspBee with the Raspberry Pi over the expansion connector. This connector provides power supply and serial port as well as one digital GPIO and the Reset pin.

The RaspBee is preprogrammed with a proprietary serial bootloader. For this bootloader, DE provides the tool GCFFlasher. It runs on the Raspberry Pi and provides a convenient and safe way to upgrade RaspBees firmware.

Caution: If you want to programm the RaspBee via the JTAG interface, the original DE bootloader firmware will be destroyed and because the flash protect fuses are set, there is no way to do backup in advance. The bootloader firmware makes the difference between the basic version (capable to handle 5 ZigBee nodes) and premium version (handles up to 200 ZigBee nodes). However upgrading the firmware with GCFFlasher is safe. You can always restore the firmware image from the DE download page.

Basic Setup

Before you can run your own firmware on the Raspberry Pi / RaspBee hardware, some prerequisite steps are required. For detailed information refer to the RaspBee User Manual.

Sonntag, 9. Juni 2013

The winners of the IPSO challenge 2013 was announed last week here. Colorado Micro Devices, you may know this guys already from the RadioBlock modules, participated in the challenge, came among the top 10 semi finalists and finally made it to the second place. How is that related to µracoli? Simply by the fact that we reused parts of this years Chemnitz Linux Days project. Especially this was Icinga, that was installed on a Raspberry-Pi and on a Cloud server. In difference to the Linux Days project we used MQTT instead of SNMP. MQTT makes it easier to operate from behind a firewall, since the local Rasperry-PI needs no official IP address, in order to be reached from the server, instead it publishes the sensor data to the cloud server actively. Thanks to the open source MQTT implementation from the Mosqitto project, we could quickly change from SNMP to the new protocoll, that fits perfectly as transport layer for sensor data.

As you may know from the news, the southern and eastern parts of germany are suffered from a flood, that is comparable to the desaster that happened in 2002. The maximum water level this time was about 10m, the historical old town of Meissen including the theatre was flooded completely. However the water recedes now but very slow. At some places where the water disappeared and the people in my neighborhood started today with cleaning their houses. (I live a few kilometers away from the river and was not suffered).

So I called somebody and asked if there is some help needed and after clearifying the details I put the Kärcher and the rubber boots in the car and went to his place. We had water from below and above, since it started to rain, so the power cables for the pumps and the pressure washers needed to kept dry and it gets a bit scary when a thunderstorm came up - so we had to interrupt the work for a while - this was a good time for a having a break and talkig about the last days.

At the end of the day it can be summarized that it is amazing to experience the solidarity among the people. This feeling is somehow comparable to open source development. Everybody pulls trough and it is amazing to see, how step by step the chaos disappears.

Donnerstag, 23. Mai 2013

The show Dogorians (http://www.dogora.com), a musical now (May 2013) playing at the Theatre du Soleil in France, needed some compact remote wireless light fixtures.

So, in conjunction with Daniel and Axel, we created some DMX driven remote nodes. This has been made in no time: 3 weeks from first draft to product delivery. We both created the software and hardware, for both the remote nodes and the gateway.

The on-field setup was easy: set the dip switch addresses, hook the gateway on the DMX light board, over !

DMX having a rather high transfer rate (250kbps), we had to use some low-level tricks such has writing straight from UART to TRX buffer (call it poor man's DMA :)).

We have future projects to make a full commercial product out of this first version.

At the moment, the code is not opened but feel free to ask for advice/snippets !